From someone who was iodine supplementing and became hyperthyroid...

I can tell you there is definitely such a thing as too much Iodine when you are hyperthyroid. I had been taking 6-8 drops of KI in liquid form for a year and it hadn't been an issue until I suddenly became hyperthyroid. Then I began to have bad bouts of alternating hot and cold flushing, and a terrible time sleeping. When the liquid KI ran out, my doctor sent me Iodoral (8000% RDV). The first day I took Iodoral was the day that I vowed that I would NEVER EVER take Iodine EVER AGAIN. I have never been so sick in my entire life.

Maybe the docs get that information from their patients who have been there.

~Mistral (formerly #72081)